全文获取类型
收费全文 | 41621篇 |
免费 | 3148篇 |
国内免费 | 1328篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 670篇 |
妇产科学 | 349篇 |
基础医学 | 6108篇 |
口腔科学 | 390篇 |
临床医学 | 3631篇 |
内科学 | 6082篇 |
皮肤病学 | 712篇 |
神经病学 | 2945篇 |
特种医学 | 611篇 |
外国民族医学 | 4篇 |
外科学 | 2073篇 |
综合类 | 5583篇 |
现状与发展 | 5篇 |
一般理论 | 3篇 |
预防医学 | 2747篇 |
眼科学 | 303篇 |
药学 | 10229篇 |
14篇 | |
中国医学 | 1482篇 |
肿瘤学 | 2076篇 |
出版年
2023年 | 552篇 |
2022年 | 755篇 |
2021年 | 1308篇 |
2020年 | 1229篇 |
2019年 | 1319篇 |
2018年 | 1298篇 |
2017年 | 1375篇 |
2016年 | 1311篇 |
2015年 | 1337篇 |
2014年 | 2406篇 |
2013年 | 3581篇 |
2012年 | 2277篇 |
2011年 | 2485篇 |
2010年 | 1913篇 |
2009年 | 1743篇 |
2008年 | 1695篇 |
2007年 | 1825篇 |
2006年 | 1565篇 |
2005年 | 1500篇 |
2004年 | 1329篇 |
2003年 | 1280篇 |
2002年 | 999篇 |
2001年 | 935篇 |
2000年 | 841篇 |
1999年 | 678篇 |
1998年 | 631篇 |
1997年 | 655篇 |
1996年 | 590篇 |
1995年 | 701篇 |
1994年 | 628篇 |
1993年 | 618篇 |
1992年 | 595篇 |
1991年 | 536篇 |
1990年 | 466篇 |
1989年 | 341篇 |
1988年 | 368篇 |
1987年 | 279篇 |
1986年 | 249篇 |
1985年 | 443篇 |
1984年 | 320篇 |
1983年 | 226篇 |
1982年 | 186篇 |
1981年 | 129篇 |
1980年 | 106篇 |
1979年 | 87篇 |
1978年 | 94篇 |
1977年 | 69篇 |
1976年 | 56篇 |
1975年 | 49篇 |
1974年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
《Vaccine》2016,34(33):3723-3730
Envelope glycoprotein E2 of classical swine fever virus (CSFV) is the major antigen that induces neutralizing antibodies and confers protection against CSFV infection. There are three hypervariable antigenic regions (HAR1, HAR2 and HAR3) of E2 that are different between the group 1 vaccine C-strain and group 2 clinical isolates. This study was aimed to characterize the antigenic epitope region recognized by monoclonal antibody 4F4 (mAb-4F4) that is present in the group 2 field isolate HZ1-08, but not in the C-strain, and examine its impact on neutralization titers when antisera from different recombinant viruses were cross-examined. Indirect ELISA with C-strain E2-based chimeric proteins carrying the three HAR regions showed that the mAb-4F4 bound to HAR1 from HZ1-08 E2, but not to HAR2 or HAR3, indicating that the specific epitope is located in the HAR1 region. Of the 6 major residues differences between C-strain and field isolates, Glu713 in the HAR1 region of strain HZ1-08 is critical for mAb-4F4 binding either at the recombinant protein level or using intact recombinant viruses carrying single mutations. C-strain-based recombinant viruses carrying the most antigenic part of E2 or HAR1 from strain HZ1-08 remained non-pathogenic to pigs and induced good antibody responses. By cross-neutralization assay, we observed that the anti-C-strain serum lost most of its neutralization capacity to RecC-HZ-E2 and QZ-14 (subgroup 2.1d field isolate in 2014), and vice versa. More importantly, the RecC-HAR1 virus remained competent in neutralizing ReC-HZ-E2 and QZ-14 strains without compromising the neutralization capability to the recombinant C-strain. Thus, we propose that chimeric C-strain carrying the HAR1 region of field isolates is a good vaccine candidate for classical swine fever. 相似文献
86.
Sachin B Ingle Baban D Adgaonkar Nawab P Jamadar Saleha Siddiqui Chitra R Hinge 《World Journal of Clinical Cases》2015,3(6):479-483
Crohn's disease(CD) is a chronic idiopathic inflammatory disease of gastrointestinal tract characterizedby segmental and transmural involvement of gastrointestinal tract. Ileocolonic and colonic/anorectal is a most common and account for 40% of cases and involvement of small intestine is about 30%. Isolated involvement of stomach is an extremely unusual presentation of the disease accounting for less than 0.07% of all gastrointestinal CD. To date there are only a few documented case reports of adults with isolated gastric CD and no reports in the pediatric population. The diagnosis is difficult to establish in such cases with atypical presentation. In the absence of any other source of disease and in the presence of nonspecific upper gastrointestinal endoscopy and histological findings, serological testing can play a vital role in the diagnosis of atypical CD. Recent studies have suggested that perinuclear anti-neutrophil cytoplasmic antibody and anti-Saccharomycescervisia antibody may be used as additional diagnostic tools. The effectiveness of infliximab in isolated gastric CD is limited to only a few case reports of adult patients and the long-term outcome is unknown. 相似文献
87.
目的探讨重症肌无力(MG)患者血清Titin抗体和Ryanodine受体(RyR)抗体的临床意义。方法采用ELISA法检测61例MG患者和35例健康体验者(正常对照组)的血清Titin抗体、RyR抗体、AChR抗体。结果MG组Titin抗体和RyR抗体阳性率均显著高于对照组(均P<0.001);合并胸腺瘤MG(MGT)组患者Titin抗体阳性率明显高于未合并胸腺瘤MG(NTMG)组(P<0.01);MGT组和NTMG组患者RyR抗体阳性率差异无统计学意义(P>0.05);晚发型MG患者中Titin抗体和RyR抗体阳性率均明显高于早发型MG患者(均P<0.05);全身型或重症型(ⅡA、ⅡB、Ⅲ、Ⅳ型)Titin抗体阳性率显著高于眼肌型(Ⅰ型)(P<0.01),而两组间RyR抗体阳性率未见统计学差异(P>0.05);MG患者Titin抗体和RyR抗体水平与肌无力严重程度相关分析呈正相关(r=0.520、0.487,均P<0.01)。结论Titin抗体和RyR抗体检测有助于MG的诊断,且Titin抗体有助于鉴别MG患者是否伴随胸腺瘤及进行Osserman分型。Titin抗体与RyR抗体水平还与MG患者病情的严重程度相关,可应用于评估MG患者的病情与预后。 相似文献
88.
89.
Yufei Tu Mario Gonzalez-Gronow Anton M. Kolomeyer Alice Cohen Joanna Pruzon Tatyana Milman 《Seminars in ophthalmology》2016,31(6):526-531
Purpose: To report a novel plasminogen gene mutation and detection of anti-plasminogen antibodies in a patient with ligneous conjunctivitis successfully treated with 60% fresh frozen plasma (FFP). Methods: Retrospective data collected on a 45-year-old Caucasian female presenting with unilateral chronic membranous lesions. Results: Laboratory investigation demonstrated decreased plasminogen antigen level, plasminogen activity, and rate of plasminogen activation by u-PA or t-PA, and elevated plasminogen activator inhibitor-1. Anti-plasminogen IgG and IgA antibodies were detected. DNA analysis revealed a novel Asp432Asn heterozygous missense mutation in the plasminogen gene (exon 11). The patient was treated with topical 60% FFP, achieved complete remission after four months, and remained membrane-free for over five years of follow-up. Conclusions: A novel plasminogen gene mutation, deficiency of plasminogen antigen and activity, and anti-plasminogen IgG and IgA antibodies were identified in a patient with adult-onset ligneous conjunctivitis. Sixty percent FFP maintained this patient disease-free for over five years. 相似文献
90.
When living organisms become sick as a result of a bacterial infection, a suite of brain-mediated responses occur, including fever, anorexia and sleepiness. Systemic administration of lipopolysaccharide (LPS), a common constituent of bacterial cell walls, increases body temperature and non-rapid eye movement (NREM) sleep in animals and induces the production of pro-inflammatory prostaglandins (PGs). PGE2 is the principal mediator of fever, and both PGE2 and PGD2 regulate sleep–wake behavior. The extent to which PGE2 and PGD2 are involved in the effect of LPS on NREM sleep remains to be clarified. Therefore, we examined LPS-induced changes in body temperature and NREM sleep in mice with nervous system-specific knockouts (KO) for the PGE2 receptors type EP3 or EP4, in mice with total body KO of microsomal PGE synthase-1 or the PGD2 receptor type DP, and in mice treated with the cyclooxygenase (COX) inhibitor meloxicam. We observed that LPS-induced NREM sleep was slightly attenuated in mice lacking EP4 receptors in the nervous system, but was not affected in any of the other KO mice or in mice pretreated with the COX inhibitor. These results suggest that the effect of LPS on NREM sleep is partially dependent on PGs and is likely mediated mainly by other pro-inflammatory substances. In addition, our data show that the main effect of LPS on body temperature is hypothermia in the absence of nervous system EP3 receptors or in the presence of a COX inhibitor. 相似文献